1. Field of the Invention
The present invention relates to a laser irradiation method for performing laser irradiation efficiently. Further, the present invention relates to a method for manufacturing a semiconductor device, which includes the process of laser irradiation.
2. Description of the Related Art
In recent years, individual recognition technology has attracted attention. For example, there is a technology to be applied to production and management, with which information such as a history of an object is clarified by giving an ID (identification code) to the individual object. Above all, the developments of semiconductor devices that can send and receive data without contact have been advanced. As such semiconductor devices, in particular, an RFID (abbreviation of Radio Frequency Identification) tag (also referred to as an ID tag, an IC tag, and IC chip, an RF (Radio Frequency) tag, a wireless tag, an electronic tag, or a wireless chip) or the like is beginning to be used in businesses, markets, and the like.
Many of semiconductor devices that have already been put to practical use each have a circuit using a semiconductor substrate such as a Si substrate (also referred to as an IC (Integrated Circuit) chip) and an antenna, and the IC chip includes a memory circuit (also referred to as a memory), a control circuit, and the like. A high-value-added semiconductor device providing higher performance can be provided particularly by mounting a memory circuit which stores much data.
Further, such semiconductor devices are required to be manufactured at low cost. Correspondingly, an organic memory element provided with an organic compound layer between a pair of electrodes has been proposed in recent years (for example, Reference 1: Japanese Published Patent Application No. 2005-116682). As a method for writing data into such an organic memory element, methods using electric action or optical action have been proposed. In the case of writing data by electric action, data “0” and data “1” are distinguished from each other based on the difference between the resistances of an area in which a pair of electrodes is short-circuited by applying high voltage therebetween and another area in which the pair of electrodes is not short-circuited, respectively. On the other hand, in the case of writing data by optical action, data “0” and data “1” are distinguished from each other based on the difference between the resistances of an area in which the state of an organic compound layer is changed by irradiating the organic compound layer with a laser beam or the like and another area in which the organic compound layer is not subjected to laser irradiation, respectively.